In the process of photographing the meteorite from all angles, I noticed a strange weathering pattern, which clearly distinguished it from all other finds we had made so far. The fusion crust was preserved in patches. This patchwork pattern was either an effect of selective abrasion or the meteorite had already arrived with an incomplete coating of crust. Between those patches of fine textured crust the dark grey and quite coarse grained matrix material was visible. It was showing not the slightest hint of a chondrule. The grains of the matrix were arranged in interlocking and overlapping layers, much like the planking of a Viking longboat.
After the documentation was completed I had the pleasure to lift the stone from the ground. It was as hot as an egg pulled from a boiling kettle and I had to flip it from hand to hand to avoid burns. The meteorite had been almost completely exposed with merely 10 percent of its mass embedded in the ground. Our hopes that we had found a new achondrite were dwindling as our magnet flipped heavily onto the rock. Probably an H-type chondrite was the other’s opinion. It still did not convince me. The surface texture reminded me on the ureilites Shisr 007 and Dar al Gani 999.
Later back home, after several hours of pointless cutting and after two wasted diamond saw blades, the fact that we indeed had stumbled upon an ureilite finally seeped in. In fact the classification result would later confirm the rock as a polymict ureilite.
Ureilites are named after the type specimen which fell after a spectacular daytime fireball and loud detonations near the village of Novo-Urei, Russia, on the morning of September 4, 1886. It is widely reported that several fragments of the meteorite were eaten by the finders who believed to attain supernatural powers.
Ureilites are ultramafic achondrites primarily composed of olivine and pyroxene with high amounts of intergranular fine grained metal, sulfides, and silicates. They contain significant amounts both of amorphous carbon and its coexisting phases, such as graphite, organic carbon, carbides, cohenite, diamond and lonsdaleite. The presence of diamond in ureilites has been correlated with the high degree of shock metamorphism of the ureilite’s parent body due to one or several catastrophic impact events. The genesis of ureilites remains yet to be fully understood and no definite parent body for these intriguing achondrites has been determined yet. Current consensus is that ureilites originate from a C-type asteroid. Up to July 2009 the Meteoritical Bulletin lists only 226 known ureilites.
Unfortunately, chances for additional finds in the area were about zero. Both our teams searched for the best part of three hours, but with one or two pieces of black chert per ten square meters it was like searching the literal needle in the haystack. With the setting sun we had to continue, as we had not yet scouted a camp site for the night and there was no suitable place in sight for miles.
We found a group of shallow hills, and Thomas and I set up our camping chairs to enjoy a premium view of what promised to be a classy sunset. We were surprised that our Russian friends only stopped by for a brief cup of tea. Pjotr was by no means satisfied with the day’s success and he was hell bent to continue searching until dark, much to the regret of Ivan, who’s hopes for some much needed camp fire recreation faded. However there was nothing else for him to it but to grin and bear it. And off they went again.
Cooling down at 104°F. No tumblers, no ice.